Cavity Wall Ties - likely cost

nembot

I was advised on the possibility of having to replace the cavity wall ties in the gable end, many years ago on my first purchase. Booked a visit for a quote after about a year, the guy drilled into the mortar, showed me the tie through the viewer and said they'll all be rusty, must be replaced.

Out of interest the quote was around £900+, if I remember correctly (approx 8 years ago).

However, I went to the garden shed and pulled out a couple I'd removed when facing up some brickwork. He was a little taken aback, when he could see apart from same discolouration, there was no rust, no expansion and they were perfectly sound. Luckily a friend of a friend was a builder (second opinion, gut feeling & all that) checked them out as well. Suggested the cracks would be down to how the wall was rendered in 3 sections, rather than knackered ties, slight creep when drying or something.

It's a long winded job if you do it yourself I believe, but certainly possible. You need to take out one or two bricks, remove the old ties and replace the bricks. To use the new ties, drill through the outer and halfway into the inner brick (few bricks over, from where the old ties were removed) to use the expanding bolts, mentioned in chainsaw's post. I'm no builder (my first attempt at pointing testifies to that) but at 6k... I'd be doing it myself

Chris55_2

We had ours replaced on a house in Leeds (similar prices to those quoted). The procedure used was that they removed the existing wall ties by drilling in to the mortar. New wall ties were steel "darts" that were fired into the brickwork. The tip of one actually protruded slightly inside! It was very noisy, as you'd expect!

bobthebuilda

chainsaw wrote: »

I did some research on the net and you can buy 150 replacement wall ties for £130. I am guessing that as they are sold in packs of 150 that is enough to do an average size house. I am sure the work could be done in a day by two men.

So the question is how much is it reasonable to charge for the labour, insurrance guarantee, profit and so on and I would say anything over £1500 is too much but I supose it depends on the going rate.

I should say I have knocked a lot of holes in walls over the years and never seen a rusty rotted tie yet. A friend of mine had an inspection of his ties done with a camera and was told they were rusty as proved by the camera seeing just one rusty tie!! He got out his hammer and chisel removed a couple of bricks and took out the tie showing that it was not rusty at all.

well done mate been replacing wall ties for 25 years you were correct on 2 points 1, depending on size the job can be done in a day. 2, for your average 3 bed semi should easily be below £1500.00
But my advice to you and others is to ask for the company you have asked to do a survey is to extract a wall tie so you can physically see corrosion. All i can say is that wall tie coorosion is very very common especially in properties which were built with black ash mortar. REMEMBER before attempting replacing any wall ties seek the appropriate advice because they are an integral part of the structure. And please dont go bumping out any bricks as this method was scrapped years ago because it caused way to much structural damage. if you need advice post a reply.

SteveV2

This could be done quite easily by yourself.

Have a look in the screwfix book, or their website. Have a look at helifix.

You will find wall ties that can be drilled through your wall and into the other side of the cavity. It's all held in pace with resin. I used to use helifix all the time a few years ago. Really easy to do and turns an expensive job into an easy one, and one you can do yourself.

From memory (it was a while back). Work out your cavity size, drill a hole into the cavity to work it out. Once you have that work out what ties you need. Your cavity will most likely be 75mm so if you get 180mm ties you can get a 52,5mm tie into each side of each wall. Just drill into the first skin until you are though. Once there push the drill until you hit the toher skin. Now drill 52mm, maybe mark the drill bit.

Now fill the heligun with the resin, insert a tie into the end and keep triggering the gun until the resit comes out the end. The tie will want to keep coming out due it it's design but just keep pushing it back, not with you finger, sharp as! Once there put the heli gun through your hole, though the cavity and into the other hole and trigger away. The tie will come out, coated in resin and will seal itself into each skin. Bit of sand and cement (and maybe a touch of lime) and point the drill hole up

I don't know the spec on how far apart, how high from one antoher but as a guide a normal wall tie should have 3 whle brick between and be every 6 courses. Alternating so making a diamond pattern. Every 3 coarses up the window and door.

A pack of 50 180mm ties is £21.xx.

Why anyone would take a skin down to replace actual ties is beyond me.

There could have been another way without the resin, but it really has been a while!

paulb487

An alternative is to inject polyurethane foam into the cavity. This glues the two walls together avoiding the need to replace the wall ties.

The polyurethane foam also insulates the cavity and (depending on what figures you want to pick) is twice as good as blown mineral wool fibre or polystyrene bead. Polyurethane is also impervious to water so won't be affected by flooding or water ingress (unlike mineral wool - think soggy kitten).

Isothane Technitherm and BASF WallTite are the only two certified products on the market that I know of. They ain't cheap, typically quoting £2k for a semi detached, but if you can kill two birds with one stone...

duck1978

Hi,

We have just purchased a house and been quoted £3200 for the wall tie replacements??

I was unsure at first then after doing some research on Helifix and Twistfix realised that the price was a complete rip off. Getting a second opinion on Wednesday just to make sure and see how much they want to charge.

Me and my father are pretty good at DIY, Im okay, he is very good and we looked at the costs for the material which equate to prob less than £300 from twist fix, you can buy a certificate guarantee against failure for 25 years also.

As this was part of our mortgage retention do we have to get the job done by someone who charges £3000 or is this something we can do ourselves and show the surveyor?

We need to tie in the sub floor which is just longer ties that drill into 2 joists.

Can anyone help?

King_Of_Bling

Are these wall ties needed if there is a slight crack in the wall? How can you find out if you have cavity walls? The house extension where there is slight cracking was built by the previous owner around 1986, would building regs require cavity walls in those days? how can you tell the difference between subsidence and this problem which the ties solve?
Thanks

duck1978

I think the way they tell is by pulling some bricks out and investigating the tie, we have just built an extension and there is a few cracks but thats cos the house is settling. I think wall ties have been around for ages and originally made of Iron and now galvanised steal. I have done loads of research on this but just so irritating that companys want to make tonnes out of you.

Most companies come out and do a free survey

King_Of_Bling

duck1978 wrote: »

I think the way they tell is by pulling some bricks out and investigating the tie, we have just built an extension and there is a few cracks but thats cos the house is settling. I think wall ties have been around for ages and originally made of Iron and now galvanised steal. I have done loads of research on this but just so irritating that companys want to make tonnes out of you.

Most companies come out and do a free survey

Is it easier just to claim for subsidence on an insurance policy, then let the insurance people decide if it's settling or subsidence (£1,000 i'd have to pay towards the policy claim)

duck1978

King_Of_Bling wrote: »

Is it easier just to claim for subsidence on an insurance policy, then let the insurance people decide if it's settling or subsidence (£1,000 i'd have to pay towards the policy claim)

Dont think we could as its been mentioned on the report before completion. If we do the work ourselves we will save 1000's so just need to know if the work has to be certified. You can buy a 25 year guarantee for the wall ties from twistfix and there prices are cheap (might have sounded like I was saying they were expensive earlier)